Influenza Fusogenic Peptide in DNA Complex Enhances Asialoglycoprotein Receptor-Mediated Gene Transfer to Hepatoma Cells: A Strategy for Liver-Targeting Gene Therapy.

Abstract

The asialoglycoprotein receptor-mediated gene transfer system is a useful method for targeted gene transfer to liver cells. This system is based on the finding that hepatocytes have a specific receptor for asialoglycoprotein. The efficiency of this system, however, is very low. To enhance the efficiency of this system, we examined the effect of a fusogenic peptide from influenza virus on asialoglycoprotein receptor-mediated gene transfer. It is known that this peptide disrupts the endosomal membrane at acidic pH, and allows DNA to escape from the endosome into the cytosol before attack by lysosomes. A recombinant plasmid DNA carrying a reporter gene was complexed with a poly-L-lysine-conjugated 23-residue peptide derived from influenza virus hemagglutinin HA2 N-terminal peptide and galactose-poly-L-lysine conjugate, and added to the culture of HepG2 cells. When the fusogenic peptide was incorporated into the DNA complex with the galactose-poly-L-lysine conjugate, the luciferase activity in the HepG2 cells was more than 500-fold higher than that of cells transfecred with the DNA complex without the peptide. An antibody against the asialoglycoprotein receptor blocked the transfer of the DNA complex, indicating that the DNA complex was specifically transferred into the HepG2 cells by asialoglycoprotein receptor-mediated endocytosis. Our results suggest that the asialoglycoprotein receptor-mediated gene delivery system using this fusogenic peptide may be useful for the development of gene therapy targeting the liver.